Fixed MFC MDI example.
Fixed MFC MDI example.

yk35/Visualization-Library,VizLibrary/Visualization-Library,VizLibrary/Visualization-Library,VizLibrary/Visualization-Library,VizLibrary/Visualization-Library,VizLibrary/Visualization-Library,yk35/Visualization-Library,hoopoe/Visualization-Library,hoopoe/Visualization-Library,yk35/Visualization-Library,hoopoe/Visualization-Library,VizLibrary/Visualization-Library